Alarm control for sprinkler systems.



(3. SMITH.

ALARM CONTROL FOR SPR'NKLER SYSTEMS.

APPLICATION FLED DEC. '9, I914.

Patented Apr. 6, 1915.

Wutzessesz GHET'WOOD SMITH, OF WORCESTER, MASSACHUSETTS.

ALARM CONTROL FOB SPRINKLER SYSTEMS.

Specification of Letters Patent.

Patented Apr. 6, 1915.

Application filed December 19, 1914. Serial No. 878,182.

To all whom it may concern:

Be it known that I, Cmrrwooo SMITH, a citizen of the United States, residing at Worcester, in the count of Worcester and State of Massachusetts, ve invented a new and useful Alarm Control for Sprinkler Systems, of which the following is a specification. I

This invention relates to an alarm control for sprinkler systems and particularly to means for increasing the reliability in opera tion of the alarm under certain unusual or extreme conditions.

The invention is designed for use in connection with sprinkler systems in which the alarm is connected to the supply pipe of the sprinkler system at a. point adjacent the check valve in said supply ipe. It is necessary that the alarm shou d operate whenever one or more sprinklers open and cause a flow of water through the supply pipe. It is customary to arrange the opening into the alarm pipe in the seat of the check valve so that the raising of the valve will admit water to the alarm pipe and the closing of the valve will close the pipe. This simple arrangement is open to at least two serious objections. In the first place, water hammer in the supply pipe will often momentarily raise the check valve, causing an intermittent actuation of the alarm although no sprinkler is opened. In the second place the valve in the supplg pipe is necessarily of such area that the ow through a single sprinkler is often insuflicient to keep the valve continuously open. This likewise causes an intermittent and irregllar actuation of the alarm hardly distinguishable from that produced by water hammer.

It is the object of my invention to provide an improved construction'of alarm control by the use of which such irregular actuation of the alarm will be avoided.

With this object in view, one feature of my invention consists in the provision of an auxiliary device associated with the alarm control which will be efi'ective to prevent actuation of the alarm when the valve is opened as the result of water hammer in the pp y p p A further feature of my invention consists in the provision of a construction by which continuous actuation of the alarm will be insured whenever one or more sprinkler heads are open.

My invention further consists in certain devices, arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

Two forms of my invention are shown in the drawings in which- Figurel is a partial sectional elevation showing one form of my invention and its relation to a sprinkler system; Fig. 2 is an enlarged sectional detail of a portion of the device shown in Fig. l, and Fig. 3 is an clevation partly in section of a second form of my invention.

Referring to the drawings, 10 indicates the supply pipe of a sprinkler system having any desired number of branch or service pipes 11 connected thereto, and provided with sprinklers 12. A check valve 13 is mounted in the supply pipe 10 and normally rests upon the valve seat 14, as shown in Fig. 1. The seat 14 may be grooved as shown at 15 and has an opening 16 therein communicating with an alarm pipe 17.

A suitable alarm device 18 of any desired form is connected for actuation by the flow of'water through the pipe 17. In order that the alarm 18 may not be actuated when the check valve 13 is opened by water hammer, I provide the intermediate control devices shown in Fi 'si 1 and 3. In the form shown in Fig. 1 th s device comprises a casing 20 into which two sections 17' and 17'' of the pipe 17 extend and within which said sections are provided with downwardly extendin ends 21. The ends 21 of the sections 1 a and 17 are open at their lower extremities and are positioned closely adjacent to 'adiaphragm 22, suitably supported upon the "casing 20. A rod 23 is secured to the diaphragm 22 near its center and extends upwardly through a partition 24 within the casing, the upper end of the rod being secured 'to a second diaphragm 25. A coil spring 26 may be inserted between the diaphragm 22 and the partition 24. This spring normally forces the diaphragm downwardly and permits a flow of water through the casing from the section 17 of the pipe 17 to the section 17". The portion of the casing 20 below the diaphragm 22 is connected by a pipe 27 to the supply pipe 10 at a point below the check valve 13 while that portion of the casing 20 above the diaphragm 25 is similarly connected by a pipe 28 to the supply pipe 10 at a point above the check valve 13. Suitable provision is made to prevent leakage around the pipe sections 17 and 17 and the rod23 where" they pass through the partition 24 and a vent or opening 29 may be provided in theintermed'iate ortion of the casin to prevent an accumuof water 1m through the openings in the partition 24. The operation of this intermediate control device willnow be described. Under nor mal conditions the pressure in the supply pipe 10 above the check valve is e ual to or greater than the pressure below e valve. As the diaphragms 22- and 25 are of equal area, an excess of pressure above the valve will forcethe" diaphragm 22 downwardly away from the depending ends 21 of the pipe sections 17 and 17, permitting the flow of water throngh the pipe 17 to the alarm 18 whenever the check valve 13 be raised as a fesult ofgthe of one or more of the sprinkler heads. you if the pressure above is equal to the pressure below, the w ll moved downward by the sprin'g 26 This condition obtains whenever one onmore sprinkler heads 12 are opened, the resulting How of water through the pipe 10 raisin the-check valve 13 or the secondary chec valve- 30 (hereinafter described) and v permitting water-to'flow through the p pe 17- to operate the alarm 18. is the parts of the supply ipes above andrbelow' the valve 13 are In ee commmiication, the pressure 111 the two parts must be substantially the same and the diaphragm is movedto its lower limit by the As reviously the valve 13' may. be opened as a result of water hammer m the supply ipe 10. In this eventfthe-pressure ow t valve 13will exceed pressure above thevalve and. this exowve pressure will be communicated the pipe 27 to the diaphra 22 foreing'tIiediaphragm upwardly to c osethe ends 21 of the pipe sections 17 andl'f. action will take place'substantially simulthneonsly the opening of the check valve and accordingly no flow take place through the alarm pipe. The opening of the valve by intern iitt'ent excessive pressure Below the valve 18 therefore ineffective. toring the alarm.

It has out. that the opening of. a single sprinkler often induces allow insufiicient to hold the valve 13 continuously open, the actuation of the and intermittent. To correct this irregularity I provide the construction shown onanenlerged scale in Fig. 2. This construction comprises a relatively small check valve 30 mounted upon the larger check valve. 13 and coverin a comparatively small opening 31 in the urge valve. The weights of e two valves are so proportioned that the valve will open more easily the valve 13. A stop 32 is er pressure by leakage mounted adjacent the valve 30 and this stop may be adjusted to limit the upward move ment of the valve 30. By suitable adjustment the extrenrieopen position of the valve may be so fixed that the flow through a single sprinkler will sullice to hold the valve open. A passage 33 is formed in the check valve 13, communicating at one end with the opening 31 which constitutes the seat of the valve 30 and at the other end with the groove 15 or the opening 16 into which the pipe 17 is connected. When thus constructed, the normal opening of either of the check valves 13 or 30 will cause a continuous flow of water through the pipe 17 to actuate the alarm 18.

In Fig. 3 have shown a modified arrange nent forcontrolling the flow through the pipe 17. In this form the two sections of the pipe 17, indicated in Fig. 3 as 17 and 17, are connected to a sleeve or cast lug 0 which are also connected the pipes 27 and 28. A piston 41 is mounted to slide freely with its opposite ends engagthe end portions of the pipes 27 and 28. The iston 41 is shown in its normal position in F 3 and has a reduced central portion 12 which permits flow through the pipes 17? and-ll" when the piston 41 is in this position. An increase in pressurein the pipe 27 will slide the piston; upwardly until the lower full-sized portion of the piston closes-the opening in the sleeve 49 and shuts ed the flow from the pipe 17 to the pipe 17 A stop pin 43 determines the normal position of the piston and a light coil spring 44 extends into a recess in the upper end of the piston and tends to return the piston to its normal position when displaced therefrom. The general operation of the device will be seen to be precisely similar to that ofthe form previously described.

Having thus described my invention it will be seenthat other changes and modifi cations can be made therein by those skilled in the art without dc arting from the spirit and scope theme as set forth in the claims and I donot wish to be otherwise limited to the details herein disclosed but WIiat I do is:

1'. n a spri' er system,a supp] i a check valve in said supply pipe, n a a rm pipe connected to said supply pipe and normally closed by said check valve, and a pressure-controlled auxiliary device connected to said supply pipe on both sides of said check valve, said device being efi'ective to close said alarm pipe whenever the pres sure of the supply pipe below the check valve exceedsthe pressure in said pipe above the check valve.

2. in a sprinkler system, a supply pipe, :1 check valve in said pipe, an alarm pipe connected to said sup ly pipe and normally closed by said eck valve, and an.

auxiliary device in said alarm pipe connected to said supply pipe on each side of the check valve, said auxiliary device being efiective to close the alarm pipe whenever excessive pressure occurs below the check valve.

3. In a sprinkler system, a supply pipe, a check valve in said pipe, an alarm pipe normally closed by said check valve, and a cutoff device operative upon said alarm pipe, said cut-0E device being controlled by the difference in relative pressure in said supply pipe, above and below said check valve.

4.. In a sprinkler system a supply pipe, a check valve in said pipe, an alarm pipe normally closed by said check valve and having a control portion intermediate its ends, and controlling means connected to said supply pipe on each side of said check valve, each means comprising a movable member effective to prevent flow through the control portion and the alarm pipe whenever excessive pressure occurs below the check valve.

5. In a sprinkler system, a supply pipe, a check valve in said supply pipe, an alarm pipe connected to said supply pipe and normally closed by said check valve, a valve in said alarm pipe positioned intermediate its ends, and devices for opening and closing said valve, said devices being effective to close said valve whenever the pressure in the supply pipe below the check valve exceeds the pressure above the check valve and being effective to o u said valve under all other pressure relations.

6. In a sprinkler system, a supply pipe,

a check valve in said supply pipe, an alarm pipe connected to said supply pipe and normally closed by said check valve, a piston valve slidable transvergly of said alarm pipe, and pressure connections from opposite ends of said iston valve to said supply pipe at points a ove and below said check valve, said piston valve being movable under variations in relative pressure in said supply pipe to open or close said alarm pipe.

7. In a sprinkler system, a supply pipe, a check valve in said supply pipe, an alarm pipe connected to said supply pipe and normally closed by said check valve, and a. relatively small check valve mounted on said first named check valve, the larger check valve having a passage therein communicating at one end with the alarm pipe and having its opposite end normally closed by the smaller check valve.

8. In a sprinkler system, a supply pipe, a check valve in said supply pipe, an alarm pipe connected to said supply pi e and normally closed by said check va ve, a relatively small check valve mounted on said first named check valve and connections from said small check valve to the alarm pipe, whereby the opening of either valve will permit a flow of water through the alarm pipe.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

CHETWOOD SMITH. Witnesses:

CHAS T. HAWLEY, C. Fomms'r Wesson.

Eagles of this patent may be obtained or flve cents each, by addressing the Commissioner of Patents, Washington, D. G.

It is hereby certified that in Letters Patent No. 1,134Jv45, granted Aprii b, 1915, upon the applimtion of Chetwood Smith, of Worcester. Massachusetts for an improvement in Alarm Centre! for Sprinkle? Systemsfan error appears in the printed specification requiring correction as follows: Page 3, line 20.; for thrword mu-h" rend mid; and that the said Letters Patent should he read with this correction therein that the same may conform to the record of the ease in the Patent Office.

Signed and sealed this 1st day of June, A. D., 1915.

[BEAU] I J. '1. XEWTUN,

Acting 'nmnlkvs'iom'r of Iufrms. 

